When to apply noise reduction in your workflow?

[Chrisinhouston]

A fellow LR user and I are having a philosphical dissagreement. A few years ago I attended a workshop where a well known presenter suggested that if your image has a fair amount of noise that you felt needed to be reduced you should tackle that early in your worflow, for instance after you crop, apply any lens correction, adjust exposure, highlights, shadows, whites and blacks. He said that is when you reduce noise since other sliders like contrast, textrue, clarity and dehaze can all sharpen noise which then makes it harder to reduce. Only after adjusting the various sliders under Noise Recudtion should you then add sharpening and then go back to the Basic panel to make to change contrast, etc.

My friend claims that will make no difference since and that all the sliders in LR are recirocal, what one adds another can decrease. To be honest, with the bulk of my currant work I don't have too many issues with noise, my cameras are all fairly new with the latest sensors that seem to lessen noise compared to older cameras I have owned, I only really notice it in extremely low light shots. I do know that there are a few 3rd party noise reduction programs and all of them recommend using them first to reduce noise before doing any other major editing. 

[Conrad C]

It depends on whether the edit model of the application you’re using is destructive (alters original pixels immediately, like Photoshop) or nondestructive (edits are parametric and applied only at output, in raw-oriented editors like Lightroom or Camera Raw).

In a destructive edit like applying noise reduction to a Photoshop pixel layer, it’s better to do that early so that later edits are cleaner and because you can’t change the amount after it alters the original pixels.

In nondestructive image editors like Lightroom, in terms of image quality it matters less when you do it. But it is often good to do it earlier, so that you make better judgments about detail-oriented edits like sharpening, and it’s possible to reduce it later if needed

Lightroom Classic 9.3 added a new preset type that can auto-adjust settings amounts based on ISO speed, and one of the biggest anticipated uses is to apply different amounts of noise reduction settings to images of different ISO speeds as part of a default import preset. In other words, many people will use this to have Lightroom apply automatically adjusted noise reduction before they start manual editing.